An organic compound can take various structures compared with an inorganic compound, and it is possible to synthesize a material having various functions by appropriate molecular-design of an organic compound. Owing to these advantages, photo electronics and electronics which employ a functional organic material have been attracting attention in recent years.
For example, a solar cell, a light emitting element, an organic transistor, and the like are exemplified as an electronic device using an organic compound as a functional organic material. These devices take advantage of electrical properties and optical properties of the organic compound. Among them, in particular, a light emitting element has been making remarkable progress.
It is considered that the light emission mechanism of a light emitting element is as follows: when a voltage is applied to a pair of electrodes between which a light emitting layer is interposed, electrons injected from a cathode and holes injected from an anode are recombined at a luminescent center in the light emitting layer to form a molecular exciton, and energy is released to emit light when the molecular exciton returns to the ground state. As excited states, a singlet excited state and a triplet excited state are known, and light emission is considered to be possible through either of these excited states.
In an attempt to improve the performances of such a light emitting element, there are many problems which depend on the material, and in order to solve these problems, improvement of the element structure and development of a material have been carried out.
As a material used for a light emitting element, anthracene derivatives can be given.
For example, Patent Document 1 (Japanese Published Patent Application No. 2003-142269) mentions an organic EL display which uses an anthracene derivative or the like as a host material of a red light emitting layer.
In addition, Patent Document 2 (PCT International Publication No. 2006-049316) mentions an organic electroluminescent element which uses aromatic tertiary amine having an anthracene skeleton for a hole injecting material.
As mentioned in Patent Document 1 and Patent Document 2, the anthracene derivatives are often used in light emitting elements. However, in order to put a light emitting element to practical use, development of a material with more superior characteristics has been demanded.